Plan Validation Skill | Agent Skills

Plan Validation

Overview

Validate that an implementation plan phase was correctly executed by running automated checks, comparing changes against the plan's specifications, and generating a validation report that documents completion status, deviations, and required manual testing.

When to Use

After implementing a phase from an implementation plan
After committing changes for a phase (validation works best with commits to analyze)
Before proceeding to the next phase (as a gate check)
When asked to verify or validate implementation work

Scripts

The base directory for this skill is provided when loaded.

Via Justfile

just -f {base_dir}/justfile <recipe> [args...]

| Recipe | Arguments | Description | |--------|-----------|-------------| | render | findings.json | Render to stdout | | render-stdin | - | Render from piped JSON to stdout | | save | findings.json output_dir | Save with auto-generated filename | | save-stdin | output_dir | Pipe JSON, save to directory | | schema | - | Show the expected JSON schema |

Direct Execution

uv run {base_dir}/scripts/render_report.py <findings.json> [--output-dir <dir>]

Examples

# Render to stdout, redirect to file
just -f {base_dir}/justfile render /tmp/findings.json > thoughts/shared/validate/report.md

# Render from stdin
echo '{"plan": "..."}' | just -f {base_dir}/justfile render-stdin > report.md

# Save with auto-generated filename (use absolute path)
just -f {base_dir}/justfile save /tmp/findings.json /absolute/path/to/validate/

# Direct execution with output directory
uv run {base_dir}/scripts/render_report.py findings.json --output-dir thoughts/shared/validate

Note: When using save recipes, pass an absolute path for output_dir to ensure correct placement.

Required Inputs

To validate a plan phase, the following information is needed:

| Input | Description | Example | |-------|-------------|---------| | Plan path | Location of the implementation plan | thoughts/shared/plans/2026-01-03_core-graph-validation-fixes.md | | Phase number | Which phase to validate | Phase 1 | | Worktree path | Working directory (if using worktrees) | .trees/plan-1-core-graph |

Validation Workflow

Step 1: Read the Plan Phase

Read the full implementation plan
Locate the specific phase to validate
Extract:
- What changes were specified
- Success criteria (automated and manual)
- Files that should have been modified

Step 2: Gather Evidence

Run commands to understand what was implemented:

# Check recent commits
git log --oneline -n 10

# See what changed
git diff HEAD~N..HEAD  # Where N covers the phase's commits

# Check current status
git status

Step 3: Run Automated Verification

Execute the success criteria commands from the plan. Common patterns:

# TypeScript/JavaScript projects
bun test                    # Run tests
bun run typecheck          # Type checking
bun run lint               # Linting

# Or if using make
make check                  # Combined checks
make test                   # Tests only
make build                  # Build verification

Document each result as pass (✓) or fail (✗).

Step 4: Compare Against Plan

For each item in the phase:

Check completion claims - If the plan marks something as done, verify the code exists
Verify implementation matches spec - Does the code do what the plan specified?
Look for deviations - Improvements, shortcuts, or missing pieces
Assess edge cases - Were error conditions handled?

Use codebase analysis as needed:

codebase-locator to find modified files
codebase-analyzer to examine implementation details
codebase-pattern-finder to verify patterns were followed

Step 5: Generate Validation Report

Structure findings as JSON and use the render script:

{
  "plan": "plan-alias",
  "plan_path": "thoughts/shared/plans/...",
  "phase": 1,
  "phase_title": "Graph Logic Fixes",
  "branch": "implement/plan-1",
  "commit": "abc1234",
  "verdict": "PROCEED",
  "summary": "Phase 1 implemented correctly with all tests passing.",
  "code_review": {
    "critical": [],
    "warnings": [],
    "suggestions": ["Consider adding edge case test"],
    "patterns": {"passed": ["Error handling", "Naming conventions"], "concerns": []}
  },
  "plan_validation": {
    "checks": {
      "tests": {"result": "pass", "detail": "665 pass, 0 fail"},
      "types": {"result": "pass", "detail": "clean"},
      "lint": {"result": "pass", "detail": "no issues"}
    },
    "steps": [
      {"id": "1.1", "description": "Write failing tests", "status": "complete"},
      {"id": "1.2", "description": "Remove parent blocking", "status": "complete"}
    ],
    "deviations": [],
    "manual_tests": ["Verify backlog blocked shows correct count"]
  },
  "next_steps": ["Proceed to Phase 2"]
}

Then render:

just -f {base_dir}/justfile render findings.json > thoughts/shared/validate/report.md

Validation Checklist

Always verify:

[ ] All phase steps marked complete are actually implemented
[ ] Automated tests pass (bun test)
[ ] Type checking passes (bun run typecheck)
[ ] Linting passes (bun run lint)
[ ] Code follows existing codebase patterns
[ ] No regressions introduced (existing tests still pass)
[ ] Error handling is present and robust
[ ] Success criteria from plan are met

Report Output

The render_report.py script generates a structured markdown report with:

Header - Plan, phase, branch, commit, date
Verdict - PROCEED / PROCEED WITH NOTES / BLOCKED with summary
Part 1: Code Review - Critical issues, warnings, suggestions, pattern compliance
Part 2: Plan Validation - Automated checks table, implementation status, deviations, manual tests
Next Steps - Action items based on verdict

The script handles all formatting mechanically. Focus on gathering accurate findings in the JSON structure.

After Validation

Save the report to thoughts/shared/validate/
Run thoughts sync to commit the validation report
Present findings to the user with:
- Summary: Pass/Fail/Partial
- Critical issues requiring attention
- Path to full report
- Recommendation: proceed or fix first

Agent Skills: Plan Validation

Install this agent skill to your local

Skill Files